The invention relates to a semiconductor device, and more particularly, to the inter-element isolation of a semiconductor device having circuits or elements mounted thereon which operate at a high frequency.
A plurality of elements or circuits are mounted on a single chip in order to achieve a higher level of integration, multiple functions, reduced cost and a reduction in size. To reduce the influences of these circuit elements on each other, an inter-element isolation region is formed between the elements. In one technique of providing inter-element isolation, an isolation region located between circuit elements is directly connected to the ground ohmically, thus stabilizing the potential of the isolation region. In another technique, an insulator is interposed between circuit elements and serves as an isolation region that electrically separates adjacent elements from each other.
However, the above-described inter-element isolation techniques fail to pay adequate consideration to high frequency circuits. Thus, there is insufficient isolation between circuits or elements with high frequency signals, allowing mutual interference to occur between the high frequency signals, which causes unstable operation of the semiconductor device.
It is an object of the invention to provide a semiconductor device which operates at a high frequency in a stable manner.